Micro-Dual Stage Actuated Gimbal Design

ABSTRACT

A flexure assembly is described. The flexure assembly includes a gimbal portion on configured to receive a slider. The gimbal portion includes a first surface and a second surface which is opposite to the first surface. The slider is mounted on the second surface. The flexure assembly also includes a pair of microactuator elements. The flexure assembly also includes a tongue of the gimbal portion on which the slider is mounted. The tongue includes a dimple point which represents the center of the tongue. The flexure assembly also includes a pair of first supporting portions and a pair of second supporting portions of the gimbal portion. A pair of end portions are individually secured to the tongue and the first supporting portions and the pair of second supporting portions. The flexure assembly also includes a conductive circuit portion unsupported between a first stationary part and the pair of end portions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.15/931,412, filed on May 13, 2020, which claims priority from U.S.Provisional Patent Application No. 62/852,783, filed on May 24, 2019,which is hereby incorporated by reference in its entirety.

FIELD

Embodiments of the disclosure relate to the field of suspension devicesfor disk drives. More particularly, this disclosure relates to the fieldof dual stage actuated gimbal configurations for a suspension device.

BACKGROUND

A typical disk drive unit includes a spinning magnetic disk containing apattern of magnetic storage medium ones and zeroes. The pattern ofmagnetic storage medium ones and zeroes constitutes the data stored onthe disk drive. The magnetic disk is driven by a drive motor. The diskdrive unit also includes a disk drive suspension to which a magneticread/write head is mounted proximate a distal end of load beam. The“proximal” end of a suspension or load beam is the end that issupported, i.e., the end nearest to the base plate which is swaged orotherwise mounted to an actuator arm. The “distal” end of a suspensionor load beam is the end that is opposite the proximal end, i.e., the“distal” end is the cantilevered end.

The suspension is coupled to an actuator arm, which in turn is coupledto a voice coil motor that moves the suspension arcuately in order toposition the head slider over the correct data track on the data disk.The head slider is carried on a gimbal which allows the slider to pitchand roll so that it follows the proper data track on the disk, allowingfor such variations as vibrations of the disk, inertial events such asbumping, and irregularities in the disk's surface.

In a DSA suspension a small actuator located on the suspension moves thehead slider in order to position the head slider over the correct datatrack. The actuator provides both finer positioning of the head sliderthan does the voice coil motor, and provides higher servo bandwidth thandoes the voice coil motor. The actuator may be located in various placeson the suspension depending on the particular DSA suspension design.Typically, left- and right-side actuators act in push-pull fashion torotate the load beam or the distal end of the load beam.

SUMMARY

A flexure assembly is provided herein. The flexure assembly includes agimbal portion on which a slider is mounted. The gimbal portion includesa first surface and a second surface which is opposite to the firstsurface. The slider is mounted on the second surface. The flexureassembly also includes a pair of microactuator elements. Each of thepair of microactuator elements being disposed on a respective side ofthe slider and each includes a first end portion and a second endportion. The microactuator elements are mounted to the second surface.The flexure assembly also includes a tongue of the gimbal portion onwhich the slider is mounted. The tongue includes a dimple point whichrepresents the center of the tongue. The flexure assembly also includesa pair of first supporting portions and a pair of second supportingportions of the gimbal portion. A pair of end portions are individuallysecured to the tongue and the first supporting portions and the pair ofsecond supporting portions. The flexure assembly also includes aconductive circuit portion unsupported between a first stationary partand the pair of end portions.

In some embodiments, the conductive circuit portion includes a conductorconnected to an element of the slider. The conductor is configured toconnect to electrodes of the pair of microactuator elements. The firstsurface is configured to face a load beam. The slider, the microactuatorelements, and the conductive circuit portion are all disposed on thesecond surface, away from the load beam.

A disk drive suspension is also provided. The disk drive suspensionincludes a load beam and a flexure assembly. The load beam includes afirst stationary part and a dimple. The flexure assembly includes agimbal portion. The gimbal portion includes a first surface and a secondsurface which is opposite to the first surface. The first surface facesthe load beam. The flexure assembly also includes a tongue of the gimbalportion. The tongue includes a dimple point. The dimple point is on afirst axis which passes through a center of the dimple of the load beam.The flexure assembly also includes a pair of first supporting portionsand a pair of second supporting portions of the gimbal portion, to whicha pair of end portions are individually secured to the tongue. Theflexure assembly also includes a conductive circuit portion unsupportedbetween the first stationary part and the pair of end portions.

In some embodiments, the pair of first supporting portions areindividually secured and supported by a first stationary part. The pairof second supporting portions are individually secured and supported bya second stationary part. The pair of end portions can be U-shaped. Thetongue includes a fixed first tongue portion, a movable second tongueportion, and a movable third tongue portion. The tongue also includes afirst hinge portion formed between the fixed first tongue portion andthe movable second tongue portion. The tongue further includes a secondhinge portion formed between the movable second tongue portion and themovable third tongue portion.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the advantages and features ofthe disclosure can be obtained, embodiments of the present disclosureare described with reference to specific examples illustrated in theappended drawings. These drawings depict only example aspects ofembodiments of the present disclosure, and are therefore not to beconsidered as limiting of its scope. The principles are described andexplained with additional specificity and detail through the use of thefollowing drawings.

FIG. 1 is a perspective view showing a disk drive including a suspensionin accordance with an embodiment of the disclosure;

FIG. 2 is a top perspective view of the microactuator mounting sectionof a suspension, in accordance with an embodiment of the disclosure;

FIG. 3 is a bottom perspective view of the microactuator mountingsection of a suspension, in accordance with an embodiment of thedisclosure;

FIG. 4 is a plan view of the microactuator mounting section of asuspension, in accordance with an embodiment of the disclosure;

FIG. 5 is a side view of a load beam of a suspension, in accordance withan embodiment of the disclosure, during a low excitation of the torsionmode;

FIG. 6 is a side view of a load beam of a suspension, in accordance withan embodiment of the disclosure, during a high excitation of the torsionmode; and

FIG. 7 is a graphical representation of a resonant frequency (FRF) ofthe suspension, in accordance with an embodiment of the disclosure.

DETAILED DESCRIPTION

The embodiments of the present disclosure are described with referenceto the attached figures, wherein like reference numerals are usedthroughout the figures to designate similar or equivalent elements. Thefigures are not drawn to scale, and they are provided as exemplaryillustrations. Several aspects of the embodiments are described belowwith reference to example applications, which are not intended to limitthe scope of this disclosure. It should be understood that numerousspecific details, relationships, and methods are set forth to provide afull understanding of the embodiments.

Embodiments described herein are directed to a flexure assembly. Theflexure assembly includes a gimbal portion on which a slider is mounted.The gimbal portion includes a first surface and a second surface whichis opposite to the first surface. The slider is mounted on the secondsurface. The flexure assembly also includes a pair of microactuatorelements. Each of the pair of microactuator elements being disposed on arespective side of the slider and each includes a first end portion anda second end portion. The microactuator elements are mounted to thesecond surface. The flexure assembly also includes a tongue of thegimbal portion on which the slider is mounted. The tongue includes adimple point, which represents the point of alignment of the flexureassembly with a dimple of a load beam. The flexure assembly alsoincludes a pair of first supporting portions and a pair of secondsupporting portions of the gimbal portion. A pair of end portions areindividually secured to the tongue and the first supporting portions andthe pair of second supporting portions. The flexure assembly alsoincludes a conductive circuit portion unsupported between a firststationary part and the pair of end portions.

FIG. 1 is a perspective view showing a disk drive 1, in accordance withan embodiment of the disclosure. The disk drive 1 can include a case 2,disks 4, carriage 6, and a positioning motor (voice coil motor) 7. Thedisks 4 are rotatable about a spindle 3. The carriage 6 are turnableabout a pivot 5. The positioning motor (voice coil motor) 7 isimplemented to actuate the carriage 6, etc. It should be understood thatthe case 2 is typically sealed; the case 2 is illustrated without acover to illustrate all of the features therein.

The carriage 6 typically includes more than one carriage arms 8. Asuspension 10 is mounted on the distal end portion of each arm 8. Aslider (illustrated below in FIG. 2), which constitutes one or moreread/write heads, is provided on the distal end portion of thesuspension 10. In a state where each disk 4 rotates at high speed, anair bearing is formed between the disk and the slider 11 as air flows inbetween the disk 4 and slider 11. If the carriage 6 is turned by thepositioning motor 7, the suspension 10 moves radially relative to thedisk 4. Thereupon, the slider 11 moves to a desired track of the disk 4.

FIG. 2 is a perspective view of a microactuator mounting section 23 of asuspension 10. The suspension 10 can be supported by a load beam (notshown). The suspension can include a flexure 22. The flexure 22 supportsthe head gimbal assembly, which includes a mounting section 23. A slider11, which constitutes a read/write head, is provided on the suspension10, at the mounting section 23. In some embodiments, the slider 11includes magnetoresistive (MR) elements 28, which are capable ofconversion between magnetic and electrical signals. The MR elements 28are disposed on an end portion of the slider 11 that constitutes themagnetic head. These elements 28 serve to access data, that is, write orread data to or from the disk (shown in FIG. 1).

The microactuator mounting section 23 includes a gimbal portion 30,formed on the distal end portion of the flexure 22. Microactuatorelements 31 and 32 are disposed individually on the opposite sides ofthe slider 11 on the gimbal portion 30. Microactuator elements 31 and32, according to some embodiments, are formed of piezoelectric plates oflead zirconate titanate (“PZT”) or the like. The microactuator elements31 and 32 have the function of pivoting the slider 11 in the swaydirection by means of a structure. Attaching the microactuator elements31 and 32 onto the tongue on the same side as the slider 11 simplifiesthe manufacturing process. Furthermore, the position of themicroactuator elements 31 and 32 allows for less stringent requirementson the adhesive thickness control or vertical position control, as themicroactuator is not in between the slider and the load beam, as intraditional cases.

The suspension 10 can be configured as a dual-stage-actuator (DSA) type,meaning two microactuator elements 31 and 32 mounted in themicroactuator mounting section 23. It should be understood, anyconfigurations of microactuator elements may be implemented herein. Themicroactuator mounting section 23 can support the microactuator elements31 and 32 and the slider 11.

The flexure 22 includes a metal base 40. In some embodiments, the metalbase 40 is formed of a stainless-steel plate. The suspension 10 alsoincludes a conductive circuit portion 41 including one or moreconductors, such as traces. The conductive circuit portion 41 includes aconductor that connects to the slider 11. The conductor can also connectto electrodes of the microactuator elements 31 and 32.

A majority of the length of the conductive circuit portion 41 isunsupported by the metal base 40. The conductive circuit portion 41includes a first part 41A that overlaps with the metal base 40, and asecond part 41B that does not overlap the metal base 40. The longer pathof the second part 41B makes the second part 41B flexible. As a result,the conductive circuit portion 41 has a low contribution to thestiffness, and the configuration reduces the stiffness in comparison totraditional designs. This is discussed in greater detail with respect toFIG. 7.

FIG. 3 is a bottom view of the microactuator mounting section 23 takenfrom the opposite side of the conductive circuit portion 41. The flexure22 includes first and second stationary parts 22A and 22B, respectively.The metal base 40 of the flexure 22 includes a pair of first arms 51 and52 and a pair of second arms 53 and 54. The first arms 51 and 52 connectwith the first stationary part 22A. The second arms 53 and 54 connectwith the second stationary part 22B. The pair of first arms 51 and 52includes distal end portions 51A and 52A. The respective distal endportions 51A and 52A are U-shaped. The respective rear ends of thesecond arms 53 and 54 are adjacent to the distal end portions 51A and52A. The conductive circuit portion 41 is supported at 41A at the firststationary part 22A and partially by the distal end portions 51A and52A. In some embodiments, distal end portions 51A and 52A connected totongue 90 within 30% of the slider length as measured from the dimplepoint.

The gimbal portion 30 of the flexure 22 includes a fixed first tongueportion 91, a movable second tongue portion 92, a movable third tongueportion 94, a first hinge portion 93, and a second hinge portion 95. Thefirst hinge portion 93 is formed between the tongue portions 91 and 92.The second hinge portion 95 is formed between the tongue portions 92 and94. First supporting portions 70 and 71 are formed on the gimbal portion30. Specifically, the first supporting portions 70 and 71 connect withthe first stationary part 22A of the flexure 22 through the first arms51 and 52, respectively.

Moreover, the distal end portions 51A and 52A of the first arms 51 and52 connect with the second stationary part 22B of the flexure 22 throughthe second arms 53 and 54, respectively. Thus, the first supportingportions 70 and 71 are supported on the stationary parts 22A and 22B bythe first arms 51 and 52 and second arms 53 and 54, and can beelastically deformed relative to the load beam.

The microactuator elements 31 and 32 are secured to a pair of secondsupporting portions 72 and 73, respectively, formed on the gimbalportion 30. The first tongue portion 91 is formed between the firstsupporting portions 70 and 71, and the second tongue portion 92 betweenthe second supporting portions 72 and 73. The first hinge portion 93 isformed between the first and second tongue portions 91 and 92. Thesecond hinge portion 95 is formed between the second and third tongueportions 92 and 94. The first supporting portions 70 and 71, secondsupporting portions 72 and 73, third supporting portions 74 and 75,first, second and third tongue portions 91, 92 and 94, and hingeportions 93 and 95 all constitute a part of the metal base 40. Therespective contours of these components are formed by, for example,etching, laser ablation, or other methods of forming and shaping metal.The first, second and third tongue portions 91, 92, 94 and hingeportions 93 and 95 constitute a tongue 90 configured to have the sliderdisposed (shown in FIG. 2) thereon.

FIG. 4 is a plan view of the microactuator mounting section 23, inaccordance with an embodiment of the disclosure. The tongue 90 includesa dimple point 12, which represents the point of alignment of theflexure assembly with a dimple of a load beam. In some embodiments, thedimple point 12 is on the same axis passing through the center of thedimple of a load beam and the same axis as the rotational axis of hingeportion 93. The length of the conductive circuit portion 41 unsupportedby the metal base 40 is maximized by having the conductive circuitportion 41 connection to the tongue 90 near the dimple point 12. In someembodiments, the dimple point 12 is centered on the rotational axis ofhinge portion 93. This connection also provides a lower contribution tothe gimbal stiffness. In some embodiments, the conductive circuitportion 41 connects with the tongue 90 at a point that is within 30% ofthe slider length as measured from the dimple point 12. The metal base40 connection to the tongue 90 is also nearby the dimple point 12. Theconfiguration of the pair of first arms 51 and 52, and the second arms53 and 54, and the tongue 90 minimizes the deflection of the tongue 90when the suspension 10 is at different z-height.

The microactuator elements 31 and 32 can be relatively smaller than theslider 11, and are positioned at the leading edge side of the dimplepoint 12 for better mass balancing. In some embodiments, each of themicroactuator elements 31 and 32 can be 0.051×0.23×0.63 mm in dimension.The slider 11 has a dimension of 0.16×0.7×1.235 mm. This configurationensures better mass balancing of the tongue 90 for low gain of sway andbaseplate torsion modes. Referring momentarily to FIG. 7, the resonantfrequency (FRF) of the suspension for z-height variation of +/−0.15 mmis illustrated herein. In some embodiments, the microactuator length isconfigured to be no more than 60% of the slider length. The gimbalportion 30 is configured to mount the microactuator such that theposition of the microactuator is within 30% of the slider length asmeasured from the dimple point 12.

FIG. 5 is a side view of a load beam 200 of the suspension 10 when it isat low z-height position (closer to disk), in accordance with anembodiment of the disclosure. The load beam 200 includes a dimple. FIG.6 is a side view of a load beam 200 of the suspension 10 when it is athigh z-height (away from disk), in accordance with an embodiment of thedisclosure. As illustrated, the flexure 22 is disposed along the loadbeam 200. The slider 11 is connected to the flexure 22, as detailedabove. In the disclosed configuration, the stationary part 22A and 22Btogether with the load beam 200 has a different angle with respect todisk at different z-height while the slider remains parallel to the diskunder flying condition, as if the load beam 200 is “rotated” aboutdimple. Because of the arm 51A, 52A and circuit portion 41B areconnected to the tongue 90 nearby dimple point 12, the tongue 90 hasminimal structural deflection at different z-height. In other words, thetongue 90 is able to remain significantly horizontal despite the bendingof the load beam 200.

The disclosure is provided to enable any person skilled in the art tomake or use the disclosure. Various modifications to the disclosure willbe readily apparent to those skilled in the art, and the genericprinciples defined herein can be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notintended to be limited to the examples and designs described herein, butis to be accorded the widest scope consistent with the principles andnovel features disclosed herein.

What is claimed is:
 1. A flexure assembly comprising: a gimbal portionconfigured to receive a slider, the gimbal portion includes a firstsurface and a second surface which is opposite to the first surface, thegimbal portion is configured to receive the slider on the secondsurface; a distal stationary part at a distal end of the flexureassembly; and a distal pair of supporting portions of the gimbalportion, each of the distal pair of supporting portions are individuallysecured and supported by the distal stationary part at a distal end ofthe flexure assembly.
 2. The flexure assembly of claim 1, furthercomprising at least one microactuator element mounted on the secondsurface on a respective side of the slider and includes a first endportion and a second end portion.
 3. The flexure assembly of claim 2,wherein the first surface faces a load beam.
 4. The flexure assembly ofclaim 2, wherein the pair of end portions are U-shaped.
 5. The flexureassembly of claim 1, further comprising a conductive circuit portionunsupported from a proximate stationary part and beyond the proximatepair of supporting portions, the conductive circuit portion is disposedon the second surface.
 6. The flexure assembly of claim 1, furthercomprising a proximate pair of supporting portions individually securedand supported by a proximate stationary part.
 7. The flexure assembly ofclaim 1, further comprising a tongue of the gimbal portion on which theslider is mounted, the tongue includes a fixed first tongue portion, anda movable second tongue portion
 8. The flexure assembly of claim 7,wherein the tongue further includes a first hinge portion formed betweenthe fixed first tongue portion and the moveable second tongue portion.9. A disk drive suspension comprising: a load beam; and a flexureassembly, including: a gimbal portion configured to receive a slider,the gimbal portion includes a first surface and a second surface whichis opposite to the first surface, the gimbal portion is configured toreceive the slider on the second surface; a distal stationary part at adistal end of the flexure assembly; and a distal pair of supportingportions of the gimbal portion, each of the distal pair of supportingportions are individually secured and supported by the distal stationarypart at a distal end of the flexure assembly.
 10. The disk drivesuspension of claim 9, further comprising at least one microactuatorelement mounted on the second surface on a respective side of the sliderand includes a first end portion and a second end portion.
 11. The diskdrive suspension of claim 10, wherein the first surface faces a loadbeam.
 12. The disk drive suspension of claim 10, wherein the pair of endportions are U-shaped.
 13. The disk drive suspension of claim 9, furthercomprising a conductive circuit portion unsupported from a proximatestationary part and beyond the proximate pair of supporting portions,the conductive circuit portion is disposed on the second surface. 14.The disk drive suspension of claim 9, further comprising a proximatepair of supporting portions individually secured and supported by aproximate stationary part.
 15. The disk drive suspension of claim 9,further comprising a tongue of the gimbal portion on which the slider ismounted, the tongue includes a fixed first tongue portion, and a movablesecond tongue portion
 16. The disk drive suspension of claim 15, whereinthe tongue further includes a first hinge portion formed between thefixed first tongue portion and the moveable second tongue portion.